Platycodi Radix suppresses development of atopic dermatitis-like skin lesions

Platycodi Radix has been used to treat chronic diseases, such as bronchitis, asthma, and hyperlipidemia. In this study, we examined the effect of an aqueous extract, Changkil (CK), from the root of Platycodi Radix on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD)-like skin lesions. Administration of CK onto DNCB-induced AD-like skin lesions in NC/Nga mice ameliorated lesion intensity scores, levels of IgE, thymus and activation-regulated chemokine (TARC), TNF-α, and IL-4 in serum and ears. In contrast, CK increased level of the immunosuppressive cytokine IL-10. Histopathological examination showed reduced thickness of the epidermis/dermis and dermal infiltration of inflammatory cells in the ears. CK also suppressed TNF-α/IFN-γ-induced mRNA expression and production of TARC in HaCaT cells. CK exerts beneficial effects on AD symptoms, suggesting that CK is an effective potential therapeutic agent for AD.